A study of the responsiveness of the Six-Spot Step Test in people with multiple sclerosis

Abstract

Aims: This study aimed to evaluate the responsiveness of the Six-Spot Step Test (SSST) in people with multiple sclerosis to assess its capability as a measure for detecting changes in gait and balance capacity following a 10-week training intervention. Methods: The SSST, Timed 25-Foot Walk, and mini-BESTest were administered to 71 individuals with MS, ranging from mild to severe disability, before and after a 10-week program of progressive resistance and balance training. However, 16 patients were lost to follow-up. This study adhered to the COSMIN framework for reporting and evaluating the psychometric properties of health-related outcome measures. Results: Spearman's analyses revealed a moderate negative correlation between changes in the SSST and the mini-BESTest (rs = -0.33, p = 0.02) and changes in the SSST and the Timed 25-Foot Walk (rs = -0.37, p = 0.01). Significant median (min;max) changes and corresponding effect sizes (ES) were observed in the SSST (-1.4 (-11.4;4.7), p < 0.001, ES = -0.84), the Mini-BESTest (3 (-3;13), p < 0.001, ES = 0.89), and the Timed 25-Foot Walk (0.09 (-0.21;0.54), p < 0.001, ES = 0.71). Conclusion: The SSST serves as a sensitive measure for changes in gait and balance capacity. Furthermore, the consistently large effect sizes observed across all three gait and balance assessments following the exercise intervention suggest that these measures reflect a shared underlying construct—functional mobility—which is essential for independent community living.